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                        <h1 id="ios---sharing-database-across-targets"><a class="header" href="#ios---sharing-database-across-targets">iOS - Sharing database across targets</a></h1>
<p>In case you have multiple Xcode targets and want to share your WatermelonDB instance across them, there are 2 options to be followed: via JS or via native Swift / Objective-C.</p>
<h3 id="when-to-use-this"><a class="header" href="#when-to-use-this">When to use this</a></h3>
<p>When you want to access the same database data in 2 or more Xcode targets (Notification Service Extension, Share Extension, iMessage stickers, etc).</p>
<h3 id="how-to-do-this"><a class="header" href="#how-to-do-this">How to do this</a></h3>
<p><strong>Step 1:</strong> Setting up an App Group</p>
<p>Through Xcode, repeat this process for your <strong>main target</strong> and <strong>every other target</strong> that you want to share the database with:</p>
<ul>
<li>Click on target name</li>
<li>Click <strong>Signing and Capabilities</strong></li>
<li>Click <strong>+ Capability</strong></li>
<li>Select <strong>App Groups</strong></li>
<li>Provide your App Group name, usually <code>group.$(PRODUCT_BUNDLE_IDENTIFIER)</code> (e.g.: <code>group.com.example.MyAwesomeApp</code>)</li>
</ul>
<blockquote>
<p>Note: the App Group name must be the <strong>exact same</strong> for every target</p>
</blockquote>
<p>This tells iOS to share storage directories between your targets, and in this case, also the Watermelon database.</p>
<p><strong>Step 2</strong>: Setting up <code>dbName</code>:</p>
<p><strong>Option A</strong>: Via JS</p>
<blockquote>
<p>Note: although this method is simpler, it has the disadvantage of breaking Chrome remote debugging</p>
</blockquote>
<ol>
<li>
<p>Install <a href="https://github.com/joltup/rn-fetch-blob#installation">rn-fetch-blob</a></p>
</li>
<li>
<p>In your JS, when creating the database, get the App Group path using <code>rn-fetch-blob</code>:</p>
<pre><code class="language-ts">import { NativeModules, Platform } from 'react-native';
import { Database } from '@nozbe/watermelondb';
import SQLiteAdapter from '@nozbe/watermelondb/adapters/sqlite';
import schema from './schema';
import RNFetchBlob from 'rn-fetch-blob';

const getAppGroupPath = (): string =&gt; {
  let path = '';

  if (Platform.OS === 'ios') {
    path = `${RNFetchBlob.fs.syncPathAppGroup('group.com.example.MyAwesomeApp')}/`;
  }

  return path;
}

const adapter = new SQLiteAdapter({
  dbName: `${getAppGroupPath()}default.db`,
  schema,
});

const database = new Database({
  adapter,
  modelClasses: [
    ...
  ],
});

export default database;
</code></pre>
</li>
</ol>
<p><strong>Option B</strong>: Via native Swift / Objective-C</p>
<ol>
<li>
<p>Through Xcode, repeat this process for your <strong>main target</strong> and <strong>every other target</strong> that you want to share the database with:</p>
<ul>
<li>Edit <code>Info.plist</code></li>
<li>Add a new row with <code>AppGroup</code> as key and <code>group.$(PRODUCT_BUNDLE_IDENTIFIER)</code> (set up in Step 1) as value.</li>
</ul>
</li>
<li>
<p>Right-click your project name and click <strong>New Group</strong>.</p>
</li>
<li>
<p>Add a file named <code>AppGroup.m</code> and paste the following:</p>
<pre><code>#import &quot;React/RCTBridgeModule.h&quot;
@interface RCT_EXTERN_MODULE(AppGroup, NSObject)
@end
</code></pre>
</li>
<li>
<p>Add a file named <code>AppGroup.swift</code> and paste the following:</p>
<pre><code>import Foundation

@objc(AppGroup)
class AppGroup: NSObject {

 @objc
 func constantsToExport() -&gt; [AnyHashable : Any]! {
   var path = &quot;&quot;
   if let suiteName = Bundle.main.object(forInfoDictionaryKey: &quot;AppGroup&quot;) as? String {
     if let directory = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: suiteName) {
       path = directory.path
     }
   }

   return [&quot;path&quot;: &quot;\(path)/&quot;]
 }
}
</code></pre>
<p>This reads your new <code>Info.plist</code> row and exports a constant called <code>path</code> with your App Group path (shared directory path), to be used in your JS code.</p>
</li>
<li>
<p>In your JS, when creating the database, import the <code>path</code> constant from your new <code>AppGroup</code> module and prepend to your <code>dbName</code>:</p>
<pre><code class="language-ts">import { NativeModules, Platform } from 'react-native';
import { Database } from '@nozbe/watermelondb';
import SQLiteAdapter from '@nozbe/watermelondb/adapters/sqlite';
import schema from './schema';

const getAppGroupPath = (): string =&gt; {
  let path = '';

  if (Platform.OS === 'ios') {
    path = NativeModules.AppGroup.path;
  }

  return path;
}

const adapter = new SQLiteAdapter({
  dbName: `${getAppGroupPath()}default.db`,
  schema,
});

const database = new Database({
  adapter,
  modelClasses: [
    ...
  ],
});

export default database;
</code></pre>
</li>
</ol>
<p>This way you're telling Watermelon to store your database into the shared directories, you're ready to go!</p>

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